University of Canterbury research shows up to 80 per cent of Christchurch primary schoolers developed post-traumatic stress disorder symptoms (PTSD) after the region’s earthquake sequence, which started in 2010.

The study found the rate of PTSD is double that recorded for children in big earthquake disasters elsewhere in the world.

Researcher Kathleen Liberty said that was due to the "unprecedented" rate of aftershocks between 2010 and 2012, with over 100 shallow earthquakes magnitude 5 or greater.

She said for the children starting school "a great portion of their life would have been in this disaster community, which produces a chronic stress response".

Waltham Primary School principal Gordon Caddie said the quakes were challenging for children and affected their learning.

Too many children had waited for mental health help since the quakes.

"Kids are feeling less certain about their safety… [they’re] growing up hearing messages that we aren’t always safe, and that things can go wrong."

Caddie said schools had watched the election closely, as a change of government could have a big effect on education and the help children received.

The new Labour-led Government is promising an extra 80 mental health staff over three years to help Canterbury students.

Caddie said the Ministry of Education had tried to help Christchurch schools to keep up with children’s mental health needs, but he was looking forward to a "change in direction".

He said extra mental health staff would be fantastic for schools.

"Any help is appreciated, and hopefully that’ll bring the waiting lists down."

Watch or read more from Gordon Caddie here:

Canterbury Primary Principal Association Chairperson Margaret Trotter said although it was early days, she looked forward to working with Labour to tackle mental health issues.

She said it was important to remember how well Canterbury teachers have coped, having been through housing and family dilemmas of their own.

"They're facing classrooms on a day to day basis, and it will be great to have extra resources for this."

Canterbury District Health Board statistics show between 2011 and 2015 there was a 69 per cent increase in children and youth who requested mental health support.

Children born after the main quakes were displaying the same symptoms as those who grew up during them.

Waltham Primary School’s Deputy Principal and New Entrance teacher Janine Terawhiti said the children’s stresses were commonly secondary, dependent on how their parents were affected.

Christchurch clinical psychologist Corina Grennell said 80 extra mental health staff in schools would make a "great difference", regarding the staff have appropriate levels of expertise.

She had concerns about how Labour would find enough qualified staff, as those in the sector were already burnt out and leaving.

"Working with children is a special skill set, you’re also working with parents, you’re liaising with schools."